Here, \(\hat{{X}}_{\text{hoevd}} = {X}\cdot (\mathbf {Q}_{\text{hoevd}}\mathbf {Q}_{\text{hoevd}}^\top , \dots , \mathbf {Q}_{\text{hoevd}}\mathbf {Q}_{\text{hoevd}}^\top )\)  as in rem:core and \(\hat{{X}}_{\text{best}}\)  comes from the argmin of REF .
We observe such suboptimality later in subsec: rank and noise.
However according to [1]}, HOEVD's solution usually belongs to an “attractive" region around the desired local optima in numerical experiments, so it is a good candidate for initialization.
